1，程序：
#includeint main()
{
std::cout<<"Enter two numbers:"<
std::cin>>v1>>v2;
std::cout<<"The sum of "<
c++学习第一课--输入/输出
int main()
{
std::cout<<"Enter two numbers:"<
std::cin>>v1>>v2;
std::cout<<"The sum of "<
int main()
{
std::cout<<"Enter two numbers:"<
std::cin>>v1>>v2;
std::cout<<"The sum of "<